Pressure jacket having syringe retaining element

ABSTRACT

A pressure jacket configured for connecting to an injector head of a fluid injector has an open distal end, an open proximal end, and a sidewall defining a throughbore extending between the distal end and the proximal end along a longitudinal axis. The throughbore is configured for receiving at least a portion of a syringe. The pressure jacket has at least one syringe retaining element positioned at least partially within the throughbore. The at least one syringe retaining element is configured for engaging at least a portion of the syringe during pressurized delivery of fluid from the syringe to prevent or limit a distal movement of the syringe relative to the pressure jacket.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation application under 35 U.S.C. § 120 ofU.S. application Ser. No. 16/331,366, filed Mar. 7, 2019, which is a 371national phase application of PCT International Application No.PCT/US2017/051473, filed Sep. 14, 2017, and claims priority to U.S.Provisional Application No. 62/395,684 filed on Sep. 16, 2016, thedisclosures of which are incorporated herein by reference in theirentirety.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

The present disclosure relates generally to fluid injectors having atleast one pressure jacket and to syringes for use with the fluidinjectors having the at least one pressure jacket. More specifically,the disclosure relates to fluid injectors having at least one pressurejacket with one or more syringe retaining elements for restraining axialmovement of the syringe relative to the at least one pressure jacketduring an injection procedure.

Description of the Related Art

In many medical diagnostic and therapeutic procedures, a medicalpractitioner, such as a physician, injects a patient with one or moremedical fluids. In recent years, a number of injector-actuated syringesand powered fluid injectors for pressurized injection of medical fluids,such as a contrast solution (often referred to simply as “contrast”), aflushing agent, such as saline, and other medical fluids, have beendeveloped for use in procedures such as angiography, computed tomography(CT), ultrasound, magnetic resonance imaging (MRI), positron emissiontomography (PET), and other imaging procedures. In general, these fluidinjectors are designed to deliver a preset amount of one or more fluidsat a preset pressure and/or flow rate.

Typically, a fluid injector has at least one drive member, such as atleast one piston, that connects to a syringe plunger within the syringe.The syringe generally includes a rigid barrel with the syringe plungerbeing slidably disposed within the barrel. The piston drives the plungerin a proximal and/or distal direction relative to a longitudinal axis ofthe barrel to draw fluid into the syringe barrel or deliver the fluidfrom the syringe barrel.

Syringes for use with fluid injectors may be made of variousmedical-grade plastic materials with a certain minimum wall thickness.Syringe thickness is an important design factor, as pressures of up to1200 psi may be used during an injection procedure. During certaininjection procedures, the syringe itself is typically not capable ofwithstanding the high pressure due to excessive radial expansion undersuch pressure. Fluid injectors having at least one pressure jacket havebeen developed for enclosing at least a portion of the syringe while inuse and preventing radial expansion of the syringe due to buildup offluid pressure within the syringe. Such pressure jackets are designed towithstand the high injection pressures without appreciable radialexpansion.

Certain existing pressure jackets have a one-piece cylindrical design,where the syringe is inserted into the pressure jacket from the front(distal) end of the pressure jacket. The neck of the syringe mayprotrude from the distal end of the pressure jacket such that thesyringe may be connected to fluid lines leading to the patient. Aproximal end of the pressure jacket is typically retained on the fluidinjector by a coupling member. During an injection procedure, anexterior wall of the syringe expands against an interior wall of thepressure jacket due to the forces that act on the syringe in a radiallyoutward direction. Additionally, the syringe may experience significantaxial movement during a high pressure injection due to the axialmovement of the piston acting on the syringe. Such axial movement of thesyringe is undesirable and may lead to inaccurate volume delivery. Toprevent the axial movement of the syringe within the pressure jacket, aholding bracket or distal locking cap may be provided on the pressurejacket and/or the fluid injector.

While front loading, pressure jacketed fluid injector systems are knownin the art, improvements in the design of such pressure jacketed fluidinjector systems, and also in the design of syringes used in bothpressure jacketed and non-pressure jacketed injector systems, are andcontinue to be highly desirable. In particular, it would be desirable toprovide improved pressure jackets configured for preventing or limitingaxial movement of the syringe during an injection procedure.

SUMMARY OF DISCLOSURE

The present disclosure generally relates to fluid injectors having atleast one pressure jacket with one or more syringe retaining elementsfor preventing or limiting axial movement of the syringe relative to thepressure jacket during an injection procedure.

In some examples of the present disclosure, a pressure jacket may beconfigured for connecting to an injector head of a fluid injector. Thepressure jacket may have an open distal end, an open proximal end, and asidewall defining a throughbore extending between the distal end and theproximal end along a longitudinal axis. The throughbore may beconfigured for receiving at least a portion of a syringe. The pressurejacket may have at least one syringe retaining element positioned atleast partially within the throughbore, and at least one actuationmechanism operatively connected to the at least one syringe retainingelement. The at least one actuation mechanism may be configured to movethe at least one syringe retaining element relative to the pressurejacket between a disengaged position to permit a distal/proximalmovement of the syringe within the throughbore and an engaged positionto limit or prevent the distal movement of the syringe duringpressurized delivery of fluid from the syringe.

In some examples of the present disclosure, the at least one actuationmechanism may be axially or radially movable relative to the pressurejacket to move the at least one syringe retaining element between thedisengaged position and the engaged position. The at least one actuationmechanism may be biased to the disengaged position by a biasing member.The at least one syringe retaining element may be a plurality ofradially extendable and retractable fingers. The plurality of radiallyextendable and retractable fingers may extend radially inward from aninterior surface of the sidewall of the pressure jacket in the engagedposition and retract into a pocket recessed into the interior surface ofthe sidewall of the pressure jacket in the disengaged position. A distalend of at least a portion of the plurality of radially extendable andretractable fingers may have a retaining lip or other engagement featureconfigured to engage at least a portion of a distal end of the syringewhen the plurality of radially extendable and retractable fingers are inthe engaged position.

In some examples of the present disclosure, the at least one syringeretaining element may be a spring having a first end connected to atleast a portion of the pressure jacket and a second end connected to theat least one actuation mechanism. The spring may biased to the engagedposition. The at least one syringe retaining element may be acompressible ring positioned within a pocket recessed into an interiorsurface of the pressure jacket. The at least one actuation mechanism maycompress the compressible ring in the engaged position to move at leasta portion of the compressible ring radially inward from the interiorsurface of the sidewall of the pressure jacket. The at least one syringeretaining element may be a sleeve positioned within the throughbore ofthe pressure jacket between an interior surface of the sidewall of thepressure jacket and an exterior surface of the syringe.

In some examples of the present disclosure, a pressure jacket configuredfor connecting to an injector head of a fluid injector may have an opendistal end, an open proximal end, and a sidewall defining a throughboreextending between the distal end and the proximal end along alongitudinal axis. The throughbore may be configured for receiving atleast a portion of a syringe. The pressure jacket may have at least onesyringe retaining element positioned at least partially within thethroughbore. The at least one syringe retaining element may beconfigured for engaging at least a portion of the syringe duringpressurized delivery of fluid from the syringe to prevent or limit adistal movement of the syringe relative to the pressure jacket.

In some examples of the present disclosure, the at least one syringeretaining element may be at least one expansion pocket recessed radiallyoutward into an interior surface of the sidewall of the pressure jacket.A volume of the at least one expansion pocket may be selected to preventplastic yield of a sidewall of the syringe during the pressurizeddelivery of fluid from the syringe exceeding a predetermined thresholdpressure. A volume of the at least one expansion pocket may be selectedto maintain a predetermined axial restraining force due to radialexpansion of at least a portion of a sidewall of the syringe into the atleast one expansion pocket during the pressurized delivery of fluid fromthe syringe. The at least one expansion pocket may be circumferentiallycontinuous or discontinuous around a circumference of the interiorsurface of the sidewall of the pressure jacket. The at least oneexpansion pocket may be a plurality of expansion pockets axially offsetfrom each other. The at least one expansion pocket may be helical.

In some examples of the present disclosure, the at least one syringeretaining element may be at least one protrusion protruding radiallyinward from an interior surface of the sidewall of the pressure jacket.The at least one protrusion may be circumferentially continuous ordiscontinuous around a circumference of the inner surface of thesidewall of the pressure jacket. The at least one protrusion may be aplurality of protrusions axially offset from each other. The at leastone protrusion may be helical.

In some examples of the present disclosure, a fluid injector fordelivering fluid to a patient may have at least one injector head, andat least one pressure jacket removably connected to the at least oneinjector head. The at least one pressure jacket may have an open distalend, an open proximal end, and a sidewall defining a throughboreextending between the distal end and the proximal end along alongitudinal axis. The throughbore may be configured for receiving atleast a portion of a syringe. The pressure jacket may have at least onesyringe retaining element positioned at least partially within thethroughbore. The at least one syringe retaining element may beconfigured for engaging at least a portion of the syringe duringpressurized delivery of fluid from the syringe to prevent or limit adistal movement of the syringe relative to the at least one pressurejacket.

Various aspects of fluid injectors having at least one pressure jacketwith one or more syringe retaining elements for preventing or limitingaxial movement of the syringe relative to the at least one pressurejacket during an injection procedure are disclosed in one or more of thefollowing numbered clauses:

Clause 1. A pressure jacket configured for removably connecting to aninjector head of a fluid injector, the pressure jacket comprising: anopen distal end, an open proximal end, and a sidewall defining athroughbore extending between the distal end and the proximal end alonga longitudinal axis, the throughbore configured for receiving at least aportion of a syringe; and at least one syringe retaining elementpositioned at least partially within the throughbore; wherein the atleast one syringe retaining element is configured for engaging at leasta portion of the syringe during pressurized delivery of fluid from thesyringe to prevent or limit a distal movement of the syringe relative tothe pressure jacket.

Clause 2. The pressure jacket of clause 1, wherein the at least onesyringe retaining element comprises at least one expansion pocketrecessed radially outward into an interior surface of the sidewall ofthe pressure jacket.

Clause 3. The pressure jacket of any of clauses 1-2, wherein a volume ofthe at least one expansion pocket is selected to prevent plastic yieldof a sidewall of the syringe during the pressurized delivery of fluidfrom the syringe exceeding a predetermined threshold pressure.

Clause 4. The pressure jacket of any of clauses 1-3, wherein a volume ofthe at least one expansion pocket is selected to maintain apredetermined axial restraining force due to radial expansion of atleast a portion of a sidewall of the syringe into the at least oneexpansion pocket during the pressurized delivery of fluid from thesyringe.

Clause 5. The pressure jacket of any of clauses 1-4, wherein the atleast one expansion pocket is circumferentially continuous ordiscontinuous around a circumference of the interior surface of thesidewall of the pressure jacket.

Clause 6. The pressure jacket of any of clauses 1-5, wherein the atleast one expansion pocket is a plurality of expansion pockets axiallyoffset from each other.

Clause 7. The pressure jacket of any of clauses 1-6, wherein the atleast one expansion pocket is helical.

Clause 8. The pressure jacket of any of clauses 1-7, wherein the atleast one syringe retaining element comprises at least one protrusionprotruding radially inward from an interior surface of the sidewall ofthe pressure jacket.

Clause 9. The pressure jacket of any of clauses 1-8, wherein the atleast one protrusion is circumferentially continuous or discontinuousaround a circumference of the interior surface of the sidewall of thepressure jacket.

Clause 10. A pressure jacket configured for removably connecting to aninjector head of a fluid injector, the pressure jacket comprising: anopen distal end, an open proximal end, and a sidewall defining athroughbore extending between the distal end and the proximal end alonga longitudinal axis, the throughbore configured for receiving at least aportion of a syringe; at least one syringe retaining element positionedat least partially within the throughbore; and at least one actuationmechanism operatively connected to the at least one syringe retainingelement, wherein the at least one actuation mechanism is configured tomove the at least one syringe retaining element relative to the pressurejacket between a disengaged position to permit a distal movement of thesyringe within the throughbore and an engaged position to limit orprevent the distal movement of the syringe during pressurized deliveryof fluid from the syringe.

Clause 11. The pressure jacket of clause 10, wherein the at least oneactuation mechanism is axially or radially movable relative to thepressure jacket to move the at least one syringe retaining elementbetween the disengaged position and the engaged position.

Clause 12. The pressure jacket of clause 10 or clause 11, wherein the atleast one actuation mechanism is biased to the disengaged position by abiasing member.

Clause 13. The pressure jacket of any of clauses 10-12, wherein the atleast one syringe retaining element is a plurality of radiallyextendable and retractable fingers, wherein the plurality of radiallyextendable and retractable fingers extend radially inward from aninterior surface of the sidewall of the pressure jacket in the engagedposition and retract into a pocket recessed into the interior surface ofthe sidewall of the pressure jacket in the disengaged position.

Clause 14. The pressure jacket of any of clauses 10-13, wherein a distalend of at least a portion of the plurality of radially extendable andretractable fingers has a retaining lip configured to engage at least aportion of a distal end of the syringe when the plurality of radiallyextendable and retractable fingers are in the engaged position.

Clause 15. The pressure jacket of any of clauses 10-14, wherein the atleast one syringe retaining element comprises a spring having a firstend connected to at least a portion of the pressure jacket and a secondend connected to the at least one actuation mechanism.

Clause 16. The pressure jacket of any of clauses 10-15, wherein thespring is biased to the engaged position.

Clause 17. The pressure jacket of any of clauses 10-16, wherein the atleast one syringe retaining element comprises a compressible ringpositioned within a pocket recessed into an interior surface of thesidewall of the pressure jacket.

Clause 18. The pressure jacket of any of clauses 10-17, wherein the atleast one actuation mechanism compresses the compressible ring in theengaged position to move at least a portion of the compressible ringradially inward from the interior surface of the sidewall of thepressure jacket.

Clause 19. The pressure jacket of any of clauses 10-18, wherein the atleast one syringe retaining element is a sleeve positioned within thethroughbore of the pressure jacket between an interior surface of thepressure jacket and an exterior surface of the syringe.

Clause 20. A fluid injector for delivering fluid to a patient, the fluidinjector comprising: at least one injector head; and at least onepressure jacket connected to the at least one injector head, the atleast one pressure jacket having an open distal end, an open proximalend, and a sidewall defining a throughbore extending between the distalend and the proximal end along a longitudinal axis, the throughboreconfigured for receiving at least a portion of a syringe; and at leastone syringe retaining element positioned at least partially within thethroughbore, wherein the at least one syringe retaining element isconfigured for engaging at least a portion of the syringe duringpressurized delivery of fluid from the syringe to prevent or limit adistal movement of the syringe relative to the at least one pressurejacket.

These and other features and characteristics of the present disclosure,as well as the methods of operation and functions of the relatedelements of structures and the combination of parts and economies ofmanufacture, will become more apparent upon consideration of thefollowing description and the appended claims with reference to theaccompanying drawings, all of which form a part of this specification,wherein like reference numerals designate corresponding parts in thevarious figures. It is to be expressly understood, however, thatdrawings are for the purpose of illustration and description only.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of a fluid injector having a pair ofpressure jackets in accordance with one example of the presentdisclosure;

FIG. 2 is a front perspective view of the fluid injector of FIG. 1 shownwith a syringe installed in each pressure jacket;

FIG. 3 is a detailed perspective view of the syringes and pressurejackets shown in FIG. 2;

FIG. 4A is a side cross-sectional view of a syringe and a pressurejacket having a syringe retaining element in accordance with one exampleof the present disclosure, wherein the syringe retaining element is in adisengaged state or position;

FIG. 4B is a side cross-sectional view of the pressure jacket andsyringe shown in FIG. 4A, wherein the syringe retaining element is in anengaged state or position;

FIG. 4C is a side cross-sectional view of a syringe and a pressurejacket having a syringe retaining element in accordance with anotherexample of the present disclosure;

FIG. 4D is a side cross-sectional view of the pressure jacket andsyringe shown in FIG. 4C, wherein the syringe retaining element is in anengaged state or position;

FIG. 5A is a front perspective view of a pressure jacket having asyringe retaining element in accordance with another example of thepresent disclosure;

FIG. 5B is a side cross-sectional view of the pressure jacket shown inFIG. 5A in use with a syringe, wherein the syringe retaining element isin a disengaged state or position;

FIG. 5C is a side cross-sectional view of the pressure jacket andsyringe shown in FIG. 5B, wherein the syringe retaining element is in anengaged state or position;

FIG. 6A is a front perspective view of a pressure jacket having asyringe retaining element in accordance with another example of thepresent disclosure;

FIG. 6B is a top view of the pressure jacket and the syringe retainingelement shown in FIG. 6A;

FIG. 6C is a side cross-sectional view of the pressure jacket shown inFIG. 6A in use with a syringe, wherein the syringe retaining element isin a disengaged state or position;

FIG. 6D is a side cross-sectional view of the pressure jacket andsyringe shown in FIG. 6B, wherein the syringe retaining element is in anengaged state or position;

FIG. 7A is a front perspective view of a pressure jacket having asyringe retaining element in accordance with another example of thepresent disclosure;

FIG. 7B is a front perspective view of a syringe for use with thepressure jacket shown in FIG. 7A;

FIG. 7C is a side cross-sectional view of the pressure jacket andsyringe of FIGS. 7A-7B showing the syringe retained within the pressurejacket;

FIG. 7D is a detailed side cross-sectional view of the pressure jacketand syringe of FIG. 7C;

FIG. 8A is a side cross-sectional view of a pressure jacket having asyringe retaining element and a syringe configured for use therewith inaccordance with another example of the present disclosure;

FIG. 8B is a side cross-sectional view of a pressure jacket having asyringe retaining element and a syringe configured for use therewith inaccordance with another example of the present disclosure;

FIG. 8C is a side cross-sectional view of a pressure jacket having asyringe retaining element and a syringe configured for use therewith inaccordance with another example of the present disclosure;

FIG. 9A is a front perspective view of a pressure jacket having asyringe retaining element in accordance with another example of thepresent disclosure;

FIG. 9B is a side cross-sectional view of the pressure jacket shown inFIG. 9A in use with a syringe;

FIG. 10 is a front perspective view of a pressure jacket having asyringe retaining element in accordance with another example of thepresent disclosure;

FIG. 11A is a side cross-sectional view of a pressure jacket having asyringe retaining element in accordance with another example of thepresent disclosure, with the syringe retaining element shown in adisengaged state or position;

FIG. 11B is a side cross-sectional view of the pressure jacket shown inFIG. 11A, with the syringe retaining element shown in an engaged stateor position;

FIG. 12A is an exploded front perspective view of a pressure jackethaving a syringe retaining element in accordance with another example ofthe present disclosure;

FIG. 12B is a front perspective view of the pressure jacket shown inFIG. 12A and a syringe for use therewith;

FIG. 12C is a side cross-sectional view of the pressure jacket andsyringe of FIGS. 12A-12B showing the syringe retained within thepressure jacket;

FIG. 13A is a side cross-sectional view of a pressure jacket having asyringe retaining element in accordance with another example of thepresent disclosure, wherein the syringe retaining element is in adisengaged state or position;;

FIG. 13B is a side cross-sectional view of the pressure jacket andsyringe shown in FIG. 13A, wherein the syringe retaining element is inan engaged state or position;

FIG. 14 is a side cross-sectional view of a pressure jacket having asyringe retaining element in accordance with another example of thepresent disclosure;

FIG. 15A is a side cross-sectional view of a pressure jacket having asyringe retaining element in accordance with another example of thepresent disclosure, with the syringe retaining element shown in adisengaged state or position;

FIG. 15B is a side cross-sectional view of the pressure jacket shown inFIG. 15A, with the syringe retaining element shown in an engaged stateor position; and

FIG. 16 is a graph showing an axial load transfer efficiency as afunction of pressure in accordance with one example of the presentdisclosure.

In FIGS. 1-16, the same characters represent the same components unlessotherwise indicated.

DETAILED DESCRIPTION

As used in the specification, the singular form of “a”, “an”, and “the”include plural referents unless the context clearly dictates otherwise.

For purposes of the description hereinafter, the terms “upper”, “lower”,“right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”,“longitudinal”, and derivatives thereof shall relate to the disclosureas it is oriented in the drawing figures.

Spatial or directional terms, such as “left”, “right”, “inner”, “outer”,“above”, “below”, and the like, are not to be considered as limiting asthe invention can assume various alternative orientations.

When used in relation to a syringe and/or a pressure jacket, the term“proximal” refers to a portion of a syringe and/or a pressure jacketnearest to an injector when a syringe and/or a pressure jacket isoriented for connecting to an injector.

The term “distal” refers to a portion of a syringe and/or pressurejacket farthest away from an injector when oriented for connecting to aninjector.

The term “radial” refers to a direction in a cross-sectional planenormal to a longitudinal axis of a syringe and/or pressure jacketbetween proximal and distal ends.

The term “circumferential” refers to a direction around an inner orouter surface of a sidewall of a syringe and/or a pressure jacket.

The term “axial” refers to a direction along a longitudinal axis of asyringe and/or a pressure jacket extending between the proximal anddistal ends.

The term “flexible”, when used in connection with a syringe, means thatat least a portion of a syringe, such as a sidewall of a syringe, iscapable of bending or being bent to change a direction in which itextends.

The terms “roll over”, “rolling over”, and “rolls upon itself” refer toan ability of a first portion of a syringe, such as a proximal portionof a sidewall of a syringe, to bend approximately 180° relative to asecond portion of a syringe, such as a distal portion of a sidewall of asyringe, when urged by a piston of a fluid injector.

All numbers used in the specification and claims are to be understood asbeing modified in all instances by the term “about”. The term “about”means a range of plus or minus ten percent of the stated value.

Unless otherwise indicated, all ranges or ratios disclosed herein are tobe understood to encompass any and all subranges or subratios subsumedtherein. For example, a stated range or ratio of “1 to 10” should beconsidered to include any and all subranges between (and inclusive of)the minimum value of 1 and the maximum value of 10; that is, allsubranges or subratios beginning with a minimum value of 1 or more andending with a maximum value of 10 or less, such as but not limited to, 1to 6.1, 3.5 to 7.8, and 5.5 to 10.

The term “at least” means “greater than or equal to”.

The term “includes” is synonymous with “comprises”.

It is to be understood that the specific devices and processesillustrated in the attached drawings, and described in the followingspecification, are simply exemplary aspects of the disclosure. Hence,specific dimensions and other physical characteristics related to theexamples disclosed herein are not to be considered as limiting.

All documents, such as but not limited to issued patents and patentapplications, referred to herein, and unless otherwise indicated, are tobe considered to be “incorporated by reference” in their entirety.

Referring to the drawings in which like reference characters refer tolike parts throughout the several views thereof, the present disclosureis generally directed to fluid injectors having at least one pressurejacket with one or more syringe retaining elements for restraining axialmovement of the syringe relative to the at least one pressure jacketduring an injection procedure.

With reference to FIG. 1, a fluid injector 10 includes at least oneinjector head 12 and an injector housing 14. The injector head 12 may besupported on a support structure 13. In some examples, such as shown inFIG. 1, the fluid injector 10 may include two injector heads 12 arrangedin a side-by-side orientation. Each injector head 12 may be formed at afront end of the injector housing 14 and may be configured for receivingand retaining at least one pressure jacket 16. While FIG. 1 illustratesthe fluid injector 10 with two injector heads 12, each with acorresponding pressure jacket 16, other examples of the fluid injector10 may include a single injector head and a corresponding pressurejacket or more than two injector heads 12 with a corresponding number ofpressure jackets 16. The pressure jacket 16 may be removably attached tothe injector head 12 with one or more engagement elements 25 (shown inFIG. 5A), for example the one or more engagement elements described inPCT International Publications WO 2016/069714 and WO 2016/069711, thedisclosures of which are incorporated herein by this reference.

With continued reference to FIG. 1, each injector head 12 includes adrive member or piston 19, such as a reciprocally driven piston moved bya motor (not shown). Each piston 19 may be configured to extend into andfrom the respective injector head 12 through an opening in the front endof injector housing 14. Each piston 19 imparts a motive force to atleast a portion of a syringe disposed in pressure jacket 16, asdescribed herein.

With reference to FIG. 2, the fluid injector 10 is configured to receivea syringe 30 within each pressure jacket 16. The at least one pressurejacket 16 is typically a reusable component, while the syringe 30 istypically a single-use component. The fluid injector 10 may have atleast one bulk fluid source for filling the syringes 30 with fluid. Thebulk fluid source may be a first bulk fluid source 32 containing a firstmedical fluid, such as contrast, and a second bulk fluid source 34containing a second medical fluid, such as saline, for filling thesyringes 30 with first or second fluid contained in the first and secondbulk fluid sources 32, 34. At least one fluid path set 35 may be fluidlyconnected with a discharge end of each syringe 30 for delivering fluidfrom the syringes 30 through tubing connected to a catheter, needle, orother fluid delivery connection (not shown) inserted into a patient at avascular access site. Fluid flow into and from the at least one syringe30 may be regulated by a fluid control module (not shown). The fluidcontrol module may operate various pistons, valves, and/or flowregulating structures to regulate the delivery of the medical fluid,such as saline solution and contrast, to the patient based on userselected injection parameters, such as injection flow rate, duration,total injection volume, and/or ratio of contrast media and saline.Examples of suitable front-loading fluid injectors that may be used ormodified for use with the herein-described system, including at leastone pressure jacket 16 and syringe 30, are disclosed in PCT ApplicationPublication Nos. WO 2015/164783 and WO 2016/172467, the disclosures ofwhich are incorporated herein by reference.

In certain embodiments, suitable syringes 30 include a rollingdiaphragm-type syringe as described in WO 2015/164783 and WO 2016/172467having a flexible thin sidewall which rolls upon itself when acted uponby the piston 19 such that an outer surface of the sidewall at a foldingregion is folded in a radially inward direction as the piston 19 isadvanced from the proximal end to the distal end and such that the outsurface of the sidewall at the folding region is unfolded in a radiallyoutward direction as the piston 19 is retracted from the proximal end tothe distal end. Such rolling diaphragm syringes may be made from asuitable medical-grade plastic and have a sidewall thickness rangingfrom 0.01 inches-0.15 inches. Upon pressurization of the syringe 30 bydistal movement of the piston 19, the fluid pressure within the rollingdiaphragm syringe causes the sidewall to expand radially outward. Thiseffect is enhanced by the relative thinness of the syringe sidewallcompared to conventional syringes. As the syringe sidewall expandsradially outward, it contacts the interior surface of the pressurejacket 16, which limits further expansion of the syringe sidewall,thereby preventing breaking of the syringe wall. Under the increasedpressure, frictional forces between the expanded sidewall of the syringe30 and the interior surface of the sidewall of the pressure jacket 16prevent distal movement of the syringe 30 relative to the pressurejacket 16, thereby maintaining the syringe 30 in the pressure jacket 16.As described herein, the frictional forces between the exterior of thesidewall of the syringe 30 and the interior surface of the sidewall ofthe pressure jacket 16 may be modified and enhanced by incorporation ofretention features into the interior surface of the sidewall of thepressure jacket 16 and/or to the exterior surface of the sidewall of thesyringe 30. The increased frictional forces between these surfaces mayminimize or even eliminate the need for additional structures tomaintain the syringe 30 within the pressure jacket 16 during aninjection procedure.

With reference to FIG. 1, the at least one pressure jacket 16 is mountedto the front end of the injector housing 14 by an attachment mechanism(not shown) that allows for removable connection of the at least onepressure jacket 16 with the injector housing 14. In some examples, theat least one pressure jacket 16 may be non-removably connected to theinjector housing 14.

With reference to FIGS. 4A-4D, the at least one pressure jacket 16 mayhave a generally hollow cylindrical shape with a front or distal end 18having a syringe receiving opening 20 (shown in FIG. 1) for receivingthe syringe 30 into the pressure jacket 16. The at least one pressurejacket 16 further includes a rear or proximal end 22 configured toengage at least a portion of the fluid injector 10 and removably ornon-removably connect the at least one pressure jacket 16 to the fluidinjector 10. The at least one pressure jacket 16 has a sidewall 24extending between the distal end 18 and the proximal end 22 along alongitudinal axis 23 of the at least one pressure jacket 16. The opening20 at the distal end 18 of the at least one pressure jacket 16 defines athroughbore 26 that extends between the distal end 18 and the proximalend 22 along a longitudinal axis 23 of the pressure jacket 16. The atleast one pressure jacket 16 has an inner diameter D1 (shown in FIG. 4A)sized to snugly but removably receive the outer diameter D2 of thesyringe 30 (shown in FIG. 4A) such that the syringe 30 can be easilyinserted into and removed from the throughbore 26 without interferencewith an interior surface 28 of the pressure jacket sidewall 24. Theinterior surface 28 of the pressure jacket sidewall 24 is configured tocontact at least a portion of an exterior surface of the syringe 30 atleast during an injection procedure wherein the syringe 30 is expandedradially outward due to fluid pressure within the syringe 30. Asdescribed herein the contact between the exterior surface of syringe 30and interior surface 26 of the pressure jacket sidewall 24 may befrictionally enhanced but at least one syringe retaining element.

The at least one pressure jacket 16 may be made from a material capableof restraining an outward radial expansion of the syringe 30 during aninjection procedure. As discussed previously, the syringe 30 itself maynot be capable of withstanding the high pressures associated withcertain fluid injection procedures, for example due to the sidewallthickness. The at least one pressure jacket 16 may be used to limit theradial expansion of the syringe 30 under pressure. For example, incertain embodiments, the radial expansion of the syringe sidewall underinjection pressures may be limited to the inner diameter of the pressurejacket sidewall 24. In some examples, the at least one pressure jacket16 may be made from a medical grade material, such as medical gradeplastic, metal, or glass. In certain examples, the at least one pressurejacket 16 may be manufactured from a translucent or transparent materialso that at least a portion of a syringe 30 may be observed through thesidewall 24 of the pressure jacket 16.

The syringe 30 is adapted for use in CT, MRI, PET, and like proceduresand operable at typical operating pressures of, for example, about10-400 psi, such as 200-400 psi, depending on the viscosity of thefluid, diameter of the fluid path, and the desired rate of injection. Insome examples, the syringe 30 may be configured for use in proceduresrequiring pressures on the order to 1,200 psi, such as angiography. Thesyringe 30 may be a syringe disclosed in PCT Application Publication No.WO 2015/164783 and PCT Application Publication No. WO 2016/172467, thedisclosures of which are incorporated herein by reference. In otherexamples, the syringe 30 may be a bladder syringe described in U.S.Patent Application Publication No. 2013/023048, or a syringe describedin U.S. Pat. No. 9,180,252, the disclosures of which are incorporatedherein by reference in their entirety. In other examples, the syringe 30may be a syringe described in U.S. Pat. Nos. 5,383,858; 6,322,535;6,652,489; 9,173,995; and 9,199,033, the disclosures of which are allincorporated by reference in their entirety.

With reference to FIGS. 4A-4D, according to certain embodiments, thesyringe 30 may be a rolling diaphragm-type syringe which includes ahollow body that includes a forward or distal end 34, a rearward orproximal end 36, and a flexible sidewall 38 extending therebetween. Inuse, the proximal end 36 is configured for insertion into thethroughbore 26 such that the sidewall 38 of the syringe 30 is surroundedby the interior surface 28 of the pressure jacket 16. At least a portionof the distal end 34 of the syringe 30 may be exposed from the distalend 18 of the pressure jacket 16. In some examples, the syringe 30 maybe formed using a blow-molding technique using an injection moldedpreform. In other examples, the syringe 30 may be injection molded.

With continued reference to FIGS. 4A-4B, the proximal end 36 of thesyringe 30 connects to the closed end wall 40, and the distal end 34 ofthe syringe 30 defines a discharge neck 42 opposite the closed end wall40. The distal end 34 may have a frusto-conical shape that graduallynarrows from the sidewall 38 to the discharge neck 42. The closed endwall 40 may be shaped to interface directly with the piston 19 of thefluid injector 10 (shown in FIG. 1). For example, the closed end wall 40may define a receiving end pocket R for interfacing directly with asimilarly-shaped piston 19, which may be shaped to substantially matchthe shape of the closed end wall 40. The sidewall 38 and/or the end wall40 may have uniform or non-uniform thickness. For example, the sidewall38 may have increased thickness at the distal end 34 compared to the endwall 40. In other embodiments, the end wall 40 may have a non-uniformthickness across the receiving end pocket R.

The sidewall 38 of the syringe 30 defines a soft, pliable or flexible,yet self-supporting body that is configured to roll upon itself underthe action of the piston 19. In particular, the sidewall 38 of thesyringe 30 is configured to roll such that its outer surface is foldedand inverted in a radially inward direction as the piston 19 is moved ina distal direction, and unroll and unfold in the opposite manner in aradially outward direction as the piston 19 is retracted in a proximaldirection.

With reference to FIG. 3, the distal end 34 of each syringe 30 may beoptionally retained by a holding bracket 44 connected to the injectorhousing 14 or other retaining mechanism that prevents axial movement ofthe syringe 30 relative to the pressure jacket 16 during an injectionprocedure. The optional holding bracket 44 is movable between a first,closed position (FIG. 3) and a second, open position (FIG. 1). In theclosed position, the holding bracket 44 engages the distal end 34 of thesyringes 30 to retain each syringe 30 axially relative to the pressurejacket 16 and prevent or restrain movement of each syringe 30 in anaxial direction relative to the pressure jacket 16 during an injectionprocedure. In the open position, the holding bracket 44 is moved awayfrom engaging the distal end 34 of the syringe 30 to allow the syringe30 to be inserted into or removed from the pressure jacket 16.

With reference to FIGS. 4A-4B, according to certain embodiments, thesyringe 30 may have at least one radial flange 50 or other protrudingfeature protruding radially outward relative to the sidewall 38. In someexamples, the at least one radial flange 50 may protrude radiallyoutward relative to the sidewall 38 at the distal end 34 adjacent thedischarge neck 42. The at least one radial flange 50 may be formedintegrally with the sidewall 38 as a radial protrusion in the sidewall38. In other examples, the at least one radial flange 50 may be formedas a separate component that is removably or non-removably attached toan outer surface of the syringe 30. For example, the at least one radialflange 50 may be attached by an adhesive, via an interference fit, orany other type of mechanical connection that secures the at least oneradial flange 50 to at least a portion of an outer surface of thesyringe 30 and prevents axial movement of the at least one radial flange50 relative to the syringe 30. The at least one radial flange 50 has adiameter D3 (shown in FIG. 4A) that is larger than the inner diameter D1of the throughbore 26 of the pressure jacket 16. In this manner, the atleast one radial flange 50 limits how much of the body of the syringe 30can be inserted into the pressure jacket 16. The at least one radialflange 50 has a proximal surface 52 that is configured to contact thedistal end 18 of the pressure jacket 16. When the proximal surface 52 ofthe at least one radial flange 50 engages the distal end 18 of thepressure jacket 16, the syringe 30 cannot be inserted any further intothe throughbore 26 of the pressure jacket 16. In certain embodiments,the distal end 18 of the pressure jacket 16 may comprise a groove (notshown) around the interior circumference of the distal surface intowhich the at least one radial flange 50 may fit into, therebysubstantially centering the syringe 30 within the pressure jacket 16.Alternatively, the at least one radial flange 50 may be located on thedischarge neck 42 of the syringe 30 (see e.g., FIGS. 5B and 5C) and mayengage a feature on the injector 14 to maintain the syringe 30 withinthe pressure jacket 16 during a syringe filling or delivery process.

In various examples, the at least one radial flange 50 may becircumferentially continuous around an outer circumference of thesidewall 38 of the syringe 30. In other examples, the at least oneradial flange 50 may be discontinuous in a circumferential directionaround the outer circumference of the sidewall 38 of the syringe 30. Forexample, the at least one radial flange 50 may be formed from aplurality of segments circumferentially spaced apart from each otheraround the outer circumference of the sidewall 38. The segments of theat least one radial flange 50 may be spaced apart from each other atequal or unequal radial intervals. The segments of the at least oneradial flange 50 may have equal or unequal diameters. In some examples,two or more radial flanges 50 may be axially spaced apart from oneanother. The radial flanges 50 may have equal or unequal diameters.

In use, the at least one radial flange 50 is configured to prevent axialmovement of the syringe 30 in a proximal direction when the syringe 30is being filled with fluid. During such procedure according to anembodiment with a rolling diaphragm-type syringe in the compressedconfiguration (see, e.g., FIG. 12B), the piston 19 (shown in FIG. 1)releasably engages the end wall 40 and pulls the end wall 40 of thesyringe 30 in a proximal direction, as indicated by arrow A in FIGS. 4Aand 4C, for example, with a force between 10 to 300 lbs. The at leastone radial flange 50 restrains the distal end 34 of the syringe 30 frommoving in the proximal direction due to engagement of the proximalsurface 52 of the at least one radial flange 50 with a distally-facingsurface of the distal end 18 of the pressure jacket 16 or with a featureon injector 14. In this manner, movement of the syringe 30 in theproximal direction relative to the pressure jacket 16 can be prevented.In addition, the at least one radial flange 50 prevents the syringe 30from falling into the throughbore 26 of the pressure jacket 16 duringloading.

With continued reference to FIGS. 4A-4D, the pressure jacket 16 may haveat least one syringe retaining element 60. The at least one syringeretaining element 60 may be recessed radially outward into the interiorsurface 28 of the sidewall 24 of pressure jacket 16 to define at leastone expansion pocket 62. The volume of the at least one expansion pocket62 is desirably selected such that the syringe sidewall 38 can beexpanded into the expansion pocket 62 during an injection procedure toprovide a sufficient axial restraining force that restrains the movementof the syringe 30 relative to the pressure jacket 16 during apressurized fluid delivery process. However, the volume of the at leastone expansion pocket 62 is desirably minimized to avoid plastic yield ofthe syringe sidewall 38 due to excessive expansion of the syringesidewall during injections that exceed a predetermined threshold, suchas about 100 psi. As used herein, “plastic yield” means a permanentdeformation of a plastic sidewall of the syringe. Plastic yield of thesyringe sidewall 38 due to pressurized expansion may make it difficultto remove the radially deformed syringe from the pressure jacket 16after an injection process.

The at least one expansion pocket 62 may be formed integrally with theinterior surface 28 of the sidewall 24 of pressure jacket 16. The atleast one expansion pocket 62 has an inner diameter D4 that is largerthan the inner diameter D1 of the sidewall 24 of pressure jacket 16. Insome examples, the at least one expansion pocket 62 may be formed as oneor more through holes that extend at least partially through thesidewall 24 of the pressure jacket 16. In other examples, the at leastone syringe retaining element 60 may be one or more protrusions thatprotrude radially inward from the interior surface 28 of the sidewall 24of pressure jacket 16. The one or more protrusions may be dimensioned toallow insertion of the syringe 30 into the throughbore 26 duringloading, but provide sufficient axial restraining force when the syringesidewall 38 is expanded against the sidewall 24 of pressure jacket 16under pressure during an injection procedure to help retain the syringe30 within the pressure jacket 16. In some examples, the one or moreprotrusions that define the at least one syringe retaining element 60may be integrally formed with the pressure jacket 16, or be removably ornon-removably connected to the pressure jacket 16 as a separatecomponent. In some examples, the at least one syringe retaining element60 may have various combinations of one or more of the one or moreexpansion pockets 62 and one or more protrusions.

In various examples, the at least one expansion pocket 62 and/or one ormore protrusions may be circumferentially continuous around acircumference of the interior surface 28 of the sidewall 24 of pressurejacket 16. In other examples, the at least one expansion pocket 62and/or one or more protrusions may be discontinuous in a circumferentialdirection around the circumference of the interior surface 28 of thesidewall 24 of pressure jacket 16. For example, the at least oneexpansion pocket 62 and/or one or more protrusions may be formed from aplurality of segments circumferentially spaced apart from each otheraround the circumference of the interior surface 28 of the sidewall 24of pressure jacket 16. The segments of the at least one expansion pocket62 and/or one or more protrusions may be spaced apart from each other atequal or unequal radial intervals. The segments of the at least oneexpansion pocket 62 and/or one or more protrusions may have equal orunequal diameters. In some examples, such as shown in FIG. 4A, two ormore expansion pockets 62 may be axially spaced apart from one another.The plurality of expansion pockets 62 and/or one or more protrusions mayhave the same or different shapes, such as a C-shape, a U-shape, or anyother regular or irregular geometric shape. The plurality of expansionpockets 62 and/or one or more protrusions may have equal or unequaldiameters and/or equal or unequal axial length. The plurality ofexpansion pockets 62 may be formed as a roughened surface on at least aportion of the interior surface 28 of the sidewall 24 of pressure jacket16. In certain embodiments, the interior surface of the expansion pocket62 and/or one or more protrusions may have a roughened surface.Alternatively or in combination, the exterior surface of the sidewall 38of syringe 30 may be at least partially roughened to engage the sidewall24 of pressure jacket 16, such as substantially at the same location ofthe roughened surface of the at least a portion of the interior surface28 of the sidewall 24 of pressure jacket 16. Additionally, adjacentexpansion pockets 62 and/or one or more protrusions may be separatedfrom one another by equal or unequal axial distance. In otherembodiments, the medical grade plastics of the pressure jacket 16 andthe syringe 30 may be selected such that the frictional forces betweenthe pressure jacket 16 and the syringe 30 is maximized

In use, such as during an injection procedure where fluid is deliveredfrom the syringe 30, the at least one expansion pocket 62 and/or one ormore protrusions is configured to prevent axial movement of the syringe30 in a distal direction when fluid is being discharged from the syringe30. During such procedure, the piston 19 pushes the end wall 40 of thesyringe 30 in a distal direction, as indicated by arrow B in FIGS.4A-4B. As the distal end 34 of the syringe 30 is restrained from axialmovement by a holding bracket 44, continued distal movement of thepiston 19 builds fluid pressure within the syringe 30 (typically around50 to 350 psi). Due to a thin and flexible construction of the sidewall38, the sidewall 38 expands radially outward against the interiorsurface 28 of the sidewall 24 of pressure jacket 16. Because the atleast one expansion pocket 62 is recessed relative to the interiorsurface 28 of the sidewall 24 of pressure jacket 16, the sidewall 38 ofthe syringe 30 can expand radially outward locally in the region of theat least one expansion pocket 62. As the sidewall 38 of the syringe 30expands to fill the expansion pocket 62, the syringe 30 becomes engagedwith the pressure jacket 16 by a surface-to-surface frictional contactbetween the sidewall 38 of the syringe 30 with the interior surface 28of the sidewall 24 of pressure jacket 16 a nd the expansion pocket 62.Due to such surface-to-surface contact, the syringe 30 is prevented frommoving axially in the distal direction under the proximally directedforce of the piston 19. Further, as the injection pressure increases,the amount of frictional force between the sidewall 38 of the syringe 30with the interior surface 28 of the sidewall 24 of pressure jacket 16increases. In this manner, movement of the syringe 30 in the distaldirection relative to the pressure jacket 16 can be prevented orminimized The engagement of the syringe sidewall 38 with the expansionpocket 62 and/or one or more protrusions reduces or eliminates an axialload on the holding bracket 44. In addition, a torque load on theholding bracket 44 can be reduced or eliminated when only one syringe 30of a two syringe injector is pressurized to deliver fluid therefrom.

The axial frictional force between the exterior wall of the syringe 30and the interior surface 28 of the pressure jacket 16 and the at leastone syringe retaining element 60 is a function of a normal force (i.e.,force exerted on the exterior wall of the syringe 30 and the interiorsurface 28 of the pressure jacket 16 in a radial direction) and acoefficient of friction at the surface-to-surface interface between theexterior of the syringe 30 and the interior surface 28 of the pressurejacket 16, including the surface-to-surface contact between the exteriorof the syringe 30 and the at least one syringe retaining element 60.This axial frictional force opposes the relative axial movement of thesyringe 30 and the pressure jacket 16 during an injection procedure. Thecoefficient of friction is a function of the types of materials fromwhich the pressure jacket 16, the at least one syringe retaining element60, and the syringe 30 are made. The coefficient of friction is also afunction of surface structure, such as surface roughness, of thematerials from which the pressure jacket 16, the at least one syringeretaining element 60, and the syringe 30 are made. The coefficient offriction is further dependent on the presence of any fluid between theexterior of the syringe 30 and the interior surface 28 of the pressurejacket 16. Typically, any fluid between the syringe 30 and the pressurejacket 28 lowers the coefficient of friction, and thereby the overallfrictional force between the syringe 30 and the pressure jacket 16.

The axial frictional force between the syringe 30 and the pressurejacket 16 may be equal to or less than an axial force on the syringe 30during pressurized delivery of fluid from the syringe 30. As the fluidwithin the syringe 30 is pressurized, the syringe 30 expands or swellsin a radially outward direction to engage the interior surface 28 of thepressure jacket 16 and the at least one syringe retaining element 60.With an increase in pressure, the radial force with which the syringe 30is expanded increases, thereby increasing the normal force between thesyringe 30 and the pressure jacket 16. As the normal force increases,the axial frictional force also increases based on a coefficient offriction at the surface-to-surface interface between the exterior of thesyringe 30 and the interior surface 28 of the pressure jacket 16,including the surface-to-surface contact between the exterior of thesyringe 30 and the at least one syringe retaining element 60.

During a fluid delivery procedure, the piston 19 pushes the end wall 40of the syringe 30 in a distal direction, as indicated by arrow B inFIGS. 4B and 4D. As the distal end 34 of the syringe 30 is restrainedfrom axial movement by the holding bracket 44 (shown in FIG. 3),continued distal movement of the piston 19 builds fluid pressure withinthe syringe 30 (typically around 50 to 350 psi). Due to a thin andflexible construction of the sidewall 38, the sidewall 38 expandsradially outward against the interior surface 28 of the pressure jacket16. Because the at least one expansion pocket 62 is recessed relative tothe interior surface 28 of the pressure jacket 16, the sidewall 38 ofthe syringe 30 can expand radially outward locally in the region of theat least one expansion pocket 62, as shown in FIGS. 4B and 4D. As thesidewall 38 of the syringe 30 expands to fill the expansion pocket 62,the syringe 30 becomes engaged with the pressure jacket 16 by asurface-to-surface contact between the sidewall 38 of the syringe 30with the interior surface 28 of the throughbore 26 and the expansionpocket 62. Due to such surface-to-surface contact, the syringe 30 isprevented from moving axially in the distal direction under theproximally directed force of the piston 19. In this manner, movement ofthe syringe 30 in the distal direction relative to the pressure jacket16 can be prevented. The engagement of the syringe sidewall 38 with theexpansion pocket 62 reduces or eliminates an axial load on the holdingbracket 44. In addition, a torque load on the holding bracket 44 can bereduced or eliminated when only one syringe 30 is pressurized to deliverfluid therefrom.

In further examples, the at least one syringe retaining element 60 maybe a recess in the interior surface 28 of the sidewall 24 of pressurejacket 16 that is filled with an elastic material, such as athermoplastic elastomer or a silicone material. The elastic materialdesirably fills at least a portion of the expansion pocket 62 and issufficiently spaced apart from the syringe sidewall 38 to allowinsertion of the syringe 30 into the throughbore 26. During a fluiddelivery procedure, the syringe sidewall 38 expands radially outward tocontact the elastic material. The elastic material itself may deform,such as by being compressed, due to contact with the syringe sidewall38. The elastic material may have a higher coefficient of frictionrelative to the interior surface 28 of the sidewall 24 of pressurejacket 16. In this manner, the elastic material may “stick” to thesidewall 38 of the syringe 30, thereby reducing or eliminating axialmovement of the syringe 30 during an injection procedure. In someexamples, the elastic material may be provided within grooves and/orholes in the pressure jacket 16. The elastic material thus may define adeformable, resilient expansion zone into which the syringe sidewall 38may extend. After the fluid delivery procedure, the syringe sidewall 38reverts to its original shape, thereby decompressing the elasticmaterial into its original shape. The syringe 30 may be removed from thethroughbore 26 without interference with the elastic material. Theelastic material may be permanently attached to the interior sidewall 24of pressure jacket 16 or may be removably attached to the sidewall 24 ofpressure jacket 16 such that it may be replaced after a certain timeperiod. In other embodiments, the elastic material may be provided onthe exterior surface of the sidewall 38 of the syringe 30, for exampleat substantially the location so that the elastic material fits withinthe expansion pocket 62. According to this embodiment, the diameter ofthe syringe 30 with the elastic material may be less than the diameterof the throughbore 26.

With reference to FIGS. 5A-15B, a pressure jacket 16 having at least onesyringe retaining element 60 and a syringe 30 configured for use withthe pressure jacket 16 are shown in accordance with further examples orembodiments of the present disclosure. The components of the pressurejacket 16 and the syringe 30 shown in FIGS. 5A-15B are substantiallysimilar or identical to the pressure jacket 16 and the syringe 30described herein with reference to FIGS. 1-4B. Reference numerals inFIGS. 5A-15B are used to illustrate identical components of thecorresponding reference numerals in FIGS. 1-4B. As the previousdiscussion regarding the pressure jacket 16 and the syringe 30 generallyshown in FIGS. 1-4B is applicable to the examples of the presentdisclosure shown in FIGS. 5A-15B, only the relative differences betweenthe pressure jacket 16 and the syringe 30 generally shown in FIGS. 1-4Band the pressure jacket 16 and the syringe 30 generally shown in FIGS.5A-15B are discussed herein.

With reference to FIGS. 5A-5C, the pressure jacket 16 has at least onesyringe retaining element 60 that is configured for movement between adisengaged position or state (FIG. 5B) and an engaged position or state(FIG. 5C) due to movement of an actuation mechanism 70 (shown in FIGS.5B-5C). In various examples, the actuation mechanism 70 may be amechanical mechanism, an electrical mechanism, an electromechanicalmechanism, a pneumatic mechanism, a hydraulic mechanism, or acombination of any of these mechanisms. In some examples, the actuationmechanism 70 may be a rod 72 (shown in FIGS. 5B-5C) that is movableaxially relative to the pressure jacket 16. The rod 72 may be movableaxially relative to the pressure jacket 16 by a solenoid or a mechanicallinkage arrangement operatively connected to the piston 19 (shown inFIGS. 4A-4B). In some examples, the rod 72 may be connected to anelectrically activated component, such as a nitinol wire or anelectroactive polymer. The rod 72 may be biased to the disengagedposition or the engaged position by a biasing member 74. In someexamples, the rod 72 is biased to the engaged position by a biasingmember 74 that is configured as a spring.

With continued reference to FIGS. 5A-5C, the at least one syringeretaining element 60 has a plurality of radially extendable andretractable fingers 76 (hereinafter “retractable fingers 76”) arrangedcircumferentially within a pocket 78 extending radially outward into theinterior surface 28 of the pressure jacket 16. The plurality ofretractable fingers 76 may be circumferentially continuous around acircumference of the interior surface 28 of the distal portion of thesidewall 24 of pressure jacket 16. In other examples, the retractablefingers 76 may be discontinuous in a circumferential direction aroundthe circumference of the interior surface 28 of the distal portion ofthe sidewall 24 of pressure jacket 16. For example, the retractablefingers 76 may be formed from a plurality of segments circumferentiallyspaced apart from each other around the circumference of the interiorsurface 28 of the distal portion of the sidewall 24 of pressure jacket16. The segments of the at least one syringe retaining element 60 may bespaced apart from each other at equal or unequal radial intervals.

Each of the plurality of retractable fingers 76 is operatively connectedwith the actuation mechanism 70 such that movement of the actuationmechanism 70 between the disengaged position or state and the engagedposition or state also moves the at least some of the plurality ofretractable fingers 76 between a disengaged position (FIG. 5B) and anengaged position (FIG. 5C). In some examples, each retractable finger 76may be connected to at least a portion of a respective rod 72. Thebiasing member 74 may be arranged between a proximal end of at least oneof the retractable fingers 76 and a distal end of the pocket 78.

With continued reference to FIGS. 5B-5C, the pocket 78 has a firstinclined surface 80 at its distal end that guides the movement of theretractable fingers 76 between the disengaged position and the engagedposition. The first inclined surface 80 may be configured to guide theretractable fingers 76 both distally and radially inward relative to thepressure jacket 16. In some examples, the retractable fingers 76 mayhave a second inclined surface 82 that corresponds to the first inclinedsurface 80 of the pocket 78. In use, the second inclined surface 82 ofthe retractable fingers 76 is configured to slide along the firstinclined surface 80 of the pocket 78 such that the retractable fingers78 are moved both distally and radially inward from the disengagedposition (FIG. 5B) and the engaged position (FIG. 5C).

With continued reference to FIGS. 5B-5C, a distal end of the retractablefingers 76 has a radially inwardly-protruding retaining lip 84 that isconfigured to engage at least a portion of the frusto-conical distal end34 of the syringe 30 when the retractable fingers 76 are positioned inthe engaged position (FIG. 5C). In the engaged position, at least aportion of the retractable fingers 76 is configured to be extendedradially inward into the throughbore 26 of the pressure jacket 16 tocontact at least a portion of the sidewall 38 of the syringe 30. Duringan injection procedure, radial expansion of the syringe 30 increases acontacting force between the sidewall 38 of the syringe 30 and theretractable fingers 76 to prevent or limit axial movement of the syringe30 relative to the pressure jacket 16. Such axial movement of thesyringe 30 is further limited or prevented by interaction of theretaining lip 84 with the distal end 34 of the syringe 30. In someexamples, the retractable fingers 76 may be configured to reduce oreliminate the axial force exerted by the syringe 30 on the holdingbracket 44 during an injection procedure. In examples where theretractable fingers 76 are configured to eliminate the axial forceexerted by the syringe 30 on the holding bracket 44, the holding bracket44 need not be provided, or the holding bracket 44 may be used as asupplemental measure for axial retention of the syringe 30 within thepressure jacket 16, for example to hold the syringe 30 within thepressure jacket 16 prior to the injection procedure.

With reference to FIGS. 6A-6D, the pressure jacket 16 has at least onesyringe retaining element 60 that is configured for movement between adisengaged position or state (FIG. 6C) and an engaged position or state(FIG. 6D) due to movement of an actuation mechanism 70 (shown in FIG.6B). With reference to FIG. 6B, the actuation mechanism 70 may have alinearly movable dowel 94 configured for contacting at least a portionof a spring 86 that is movable between a disengaged position or stateand an engaged position or state with movement of the dowel 94. In someexamples, a first end 88 of the spring 86 is engaged with a pocket 90extending radially outward into the interior surface 28 (shown in FIG.6A) of the pressure jacket 16. A second end 92 of the spring 86 isoperatively connected with at least a portion of the actuation mechanism70, such as a linearly movable dowel 94. The spring 86 is wound in aplurality of coils 96 (shown in FIGS. 6C-6D) axially spaced apart fromone another.

The spring 86 may be biased to the engaged position. In the engagedposition, the coils 96 have a first diameter D4 that is smaller than theinner diameter D1 of the throughbore 26 and the outer diameter D2 of thesyringe 30 such that the coils 96 of the spring 86 contact the sidewall38 of the syringe 30. During an injection procedure, radial expansion ofthe syringe 30 increases a contacting force between the sidewall 38 ofthe syringe 30 and the coils 96 of the spring 86 to prevent or limitaxial movement of the syringe 30 relative to the pressure jacket 16.Alternatively, the spring 86 may be biased to the disengaged positionand the actuation mechanism 70 may move the spring into the engagedposition.

To move the spring 86 from the engaged position to the disengagedposition, the dowel 94 is operated to move the second end 92 of thespring 86 toward the first end 88, thereby spreading the coils 96 of thespring 86 radially apart. In the disengaged position, the coils 96 havea second diameter D5 that is larger than or equal to the inner diameterD1 of the throughbore 26 and larger than the outer diameter D2 of thesyringe 30 to allow a free insertion or removal of the syringe 30 fromthe throughbore 26 of the pressure jacket 16. Other actuation mechanismswhich move the spring 86 between the disengaged position and the engagedposition, such as lever or a clamping mechanism to move the first end 88and the second end 92 together and apart are also contemplated.

With reference to FIG. 7A, the pressure jacket 16 may have at least onesyringe retaining element 60 that is recessed radially outward into theinterior surface 28 of the sidewall 24 of pressure jacket 16 to defineat least one expansion pocket 62. The at least one expansion pocket 62has an inner diameter that is larger than the inner diameter of thethroughbore 26. In some examples, the expansion pocket 62 may becircumferentially continuous around a circumference of the interiorsurface 28 of the throughbore 26. In other examples, the expansionpocket 62 may be discontinuous in a circumferential direction around thecircumference of the interior surface 28 of the throughbore 26. Forexample, the expansion pocket 62 may be formed from a plurality ofsegments circumferentially spaced apart from each other around thecircumference of the interior surface 28 of the throughbore 26. Thesegments of the expansion pocket 62 may be spaced apart from each otherat equal or unequal radial intervals. In some examples, two or moreexpansion pockets 62 may be axially spaced apart from one another.

With reference to FIG. 7B, the syringe 30 may have at least one label 98extending around at least a portion of an exterior side of the sidewall38. In some examples, an axial position of the at least one label 98relative to the syringe 30 is fixed. For example, the at least one label98 may be adhesively affixed to the syringe 30, or it may be tightlybound around the outer part of the sidewall 38. The label 98 may be madeof a material that increases frictional forces between the sidewall 38of the syringe 30 and the sidewall 24 of pressure jacket 16, when thelabel 98 is held between the wall 38 of the syringe 30 and the sidewall24 of pressure jacket 16 when the syringe 30 is pressurized and radiallyexpanded during an injection protocol.

With continued reference to FIG. 7B, the at least one label 98 may haveone or more protrusions 100 that protrude radially outward relative tothe syringe 30 and a body 102 of the at least one label 98.Alternatively or in addition, the sidewall 38 of the syringe 30 may haveone or more protrusions, as described herein, that engage the at leastone expansion pocket 62. In some examples, the protrusion 100 may becircumferentially continuous around a circumference of the outer surfaceof the label 98. In other examples, the protrusion 100 may bediscontinuous in a circumferential direction around the circumference ofthe outer surface of the label 98. For example, the protrusion 100 maybe formed from a plurality of segments circumferentially spaced apartfrom each other around the circumference of the outer surface of thelabel 98. The segments of the protrusion 100 may be spaced apart fromeach other at equal or unequal radial intervals. In some examples, twoor more protrusions 100 may be axially spaced apart from one another.

With reference to FIGS. 7C-7D, the one or more protrusions 100 on thelabel 98 are configured to interact with the at least one expansionpocket 62 of the pressure jacket 16. When the syringe 30 is insertedinto the pressure jacket 16, the label 98 is interposed between an outersurface of the syringe 30 and an interior surface 28 of the sidewall 24of the pressure jacket 16. The one or more protrusions 100 are desirablypositioned such that its axial position corresponds to an axial positionof the at least one expansion pocket 62 on the pressure jacket 16. Theone or more protrusions 100 may be configured to expand into the atleast one expansion pocket 62 when the syringe 30 is pressurized. Whenthe syringe 30 is not pressurized, the one or more protrusions 100 arenot forcibly held within the at least one expansion pocket 62 to allowthe syringe 30 to be inserted into or removed from the pressure jacket16.

In use, such as during an injection procedure where fluid is deliveredfrom the syringe 30, the protrusion 100 is configured to prevent axialmovement of the syringe 30 in a distal direction when fluid is beingdischarged from the syringe 30. As the sidewall 38 of the syringe 30expands radially outward under pressure, the protrusion 100 on the label98 moves radially outward with movement of the sidewall 38 to engagewith the expansion pocket 62. In this manner, the label 98 becomesengaged with the pressure jacket 16 by a surface-to-surface contactbetween the protrusion 100 with the expansion pocket 62 and between thebody 102 of the label 98 with the interior surface 28 of the sidewall 24of the pressure jacket 16. Due to such surface-to-surface contact, thelabel 98, and thereby the syringe 30, is prevented from moving axiallyin the distal direction under the proximally directed force of thepiston 19. In this manner, movement of the syringe 30 in the distaldirection relative to the pressure jacket 16 can be prevented.

With reference to FIGS. 8A-8C, the pressure jacket 16 may have at leastone syringe retaining element 60 in the form of an expansion pocket 62.The expansion pocket 62 may be substantially similar or identical to theexpansion pocket 62 described herein with reference to FIGS. 4A-4B andFIGS. 7C-7D. Instead of the one or more protrusions 100 being formed onthe label 98 affixed to the syringe 30, such as described herein withreference to FIGS. 7A-7D, the syringes 30 of FIGS. 8A-8C may have theone or more protrusions 100 as an integral part of the sidewall 38 ofthe syringe 30.

With reference to FIG. 8A, the one or more protrusions 100 protruderadially outward relative to the outer surface of the syringe 30. Theone or more protrusions 100 may be formed as a plurality of individualprotrusions 100 that are discontinuous in a circumferential directionaround the circumference of the outer surface of the label 98. Forexample, the one or more protrusions 100 may be formed as a plurality ofsegments circumferentially spaced apart from each other around thecircumference of the outer surface of the syringe 30. The one or moreprotrusions 100 may be spaced apart from each other at equal or unequalradial intervals. In some examples, two or more rows of protrusions 100may be axially spaced apart from one another. Each of the protrusions100 may have an identical or different shape relative to the otherprotrusions 100. In some examples, the protrusions 100 may have asemi-spherical shape. In other examples, the protrusions may have asemi-ovoidal or semi-ellipsoidal shape. The one or more protrusions 100on the syringe 30 may be configured to align with and interact with theat least one expansion pocket 62 of the pressure jacket 16. In someexamples, the expansion pocket 62 may be formed a circumferentiallycontinuous ring around the inner circumference of the pressure jacket16. In other examples, the at least one expansion pocket 62 may be aplurality of expansion pockets 62 that corresponds to the plurality ofprotrusions 100. Each of the plurality of expansion pockets 62 may beconfigured to receive at least one of the one or more protrusions 100.The one or more protrusions 100 are desirably positioned such that theiraxial position corresponds to an axial position of the at least oneexpansion pocket 62 on the pressure jacket 16. The one or moreprotrusions 100 are configured to expand into the at least one expansionpocket 62 when the syringe 30 is pressurized. When the syringe 30 is notpressurized, the projections 100 are not substantially positioned withinthe expansion pocket 62 to allow the syringe 30 to be inserted into orremoved from the pressure jacket 16. In certain embodiments, when thesyringe 30 is not pressurized, the projections 100 are slightlypositioned within the expansion pocket 62 to allow the syringe 30 to“click” into place when inserted into pressure jacket 16 and be retainedat the proper position, and may allow syringe 30 to be readily removedfrom pressure jacket 16 upon completion of an injection protocol.

With reference to FIGS. 8B-8C, the one or more protrusions 100 arecircumferentially continuous around a circumference of the outer surfaceof the syringe 30. Similar to the interaction between the one or moreprotrusions 100 with the at least one expansion pocket 62 describedherein with reference to FIG. 8A, the one or more protrusions 100 inFIGS. 8B-8C are configured to interact with the at least one expansionpocket 62 of the pressure jacket 16. A single protrusion 100 on thesyringe 30 may be configured for interacting with a single expansionpocket 62 on the pressure jacket 16 (FIG. 8B), or a plurality of axiallyoffset protrusions 100 on the syringe 30 may be configured forinteracting with a corresponding plurality of expansion pockets 62 onthe pressure jacket 16. In use, such as during an injection procedurewhere fluid is delivered from the syringe 30, the projections 100 areconfigured to prevent axial movement of the syringe 30 in a distaldirection when fluid is being discharged from the syringe 30 underinjection pressure. As the sidewall 38 of the syringe 30 expandsradially outward under pressure, the projections 100 move radiallyoutward with movement of the sidewall 38 to engage with the expansionpocket 62. In this manner, the syringe 30 becomes engaged with thepressure jacket 16 by a surface-to-surface contact between theprotrusions 100 with the expansion pocket 62 and between an exteriorsurface of the sidewall 38 of the syringe 30 with the interior surface28 of the sidewall 24 of the pressure jacket 16. Due to suchsurface-to-surface contact, the syringe 30 is prevented from movingaxially in the distal direction under the proximally directed force ofthe piston 19.

With reference to FIGS. 9A-9B, the at least one syringe retention member60 is configured as an array of nubs 106, each of which protrudesradially inward from the interior surface 28 of the sidewall 24 ofpressure jacket 16. The nubs 106 are spaced apart from each other aroundthe circumference of the interior surface 28 of the sidewall 24 ofpressure jacket 16 at equal or unequal radial intervals. In someexamples, the nubs 106 have a semi-spherical shape with equal or unequaldiameters. In other examples, the nubs 106 may have a semi-ovoidal orsemi-ellipsoidal shape. In other examples, the nubs 106 may have anyregular or irregular geometric shape. The nubs 106 may be arranged in aplurality of radial bands 108 that are axially spaced apart from oneanother. The radial bands 108 may be separated from one another by equalor unequal axial distance.

In use, such as during an injection procedure where fluid is deliveredfrom the syringe 30, the nubs 106 are configured to prevent axialmovement of the syringe 30 in a distal direction when fluid is beingdischarged from the syringe 30. As the sidewall 38 of the syringe 30expands radially outward under pressure, the sidewall 38 of the syringe30 resiliently deforms to fill the voids 110 between the nubs 106. Inthis manner, the syringe 30 becomes engaged with the pressure jacket 16by a surface-to-surface contact between the nubs 106 and the interiorsurface 28 of the sidewall 24 of pressure jacket 16 with the sidewall 38of the syringe 30. Due to such surface-to-surface contact, the syringe30 is prevented from moving axially in the distal direction under theproximally directed force of the piston 19.

With reference to FIG. 10, the at least one syringe retention member 60is formed as a helical member 111 that protrudes radially outward intothe interior surface 28 of the sidewall 24 of the pressure jacket 16. Insome examples, the helical member 111 is formed as a projection thatextends radially inward from the interior surface 28 of the sidewall 24of pressure jacket 16. The helical member 111 may extend in acounterclockwise or a clockwise direction between the distal end 18 andthe proximal end 22 along the longitudinal axis 23 of the pressurejacket 16. The helical member 111 may extend over at least a portion ofthe longitudinal length of the pressure jacket 16. The helical member111 may have an equal or unequal pitch between successive turns 113. Inuse, the helical member 111 is configured to prevent axial movement ofthe syringe 30 (shown in FIGS. 4A-4B) in a distal direction when fluidis being discharged from the syringe 30 under injection pressure. As thesidewall 38 of the syringe 30 expands radially outward under pressure,the sidewall 38 of the syringe 30 resiliently deforms to engage therecess (or projection) defined by the helical member 111. In thismanner, the syringe 30 becomes engaged with the pressure jacket 16 by asurface-to-surface contact between the helical member 111 and theinterior surface 28 of the sidewall 24 of pressure jacket 16 with thesidewall 38 of the syringe 30. Due to such surface-to-surface contact,the syringe 30 is prevented from moving axially in the distal directionunder the proximally directed force of the piston 19 (shown in FIG. 3).

With reference to FIGS. 11A-11B, the pressure jacket 16 may have atleast one syringe retaining element 60 that is configured for movementbetween a disengaged position or state (FIG. 11A) and an engagedposition or state (FIG. 11B) due to movement of an actuation mechanism70. In various examples, the actuation mechanism 70 may be a mechanicalmechanism, an electrical mechanism, an electromechanical mechanism, apneumatic mechanism, a hydraulic mechanism, or a combination of any ofthese mechanisms. In some examples, the actuation mechanism 70 may be arod 72 that is movable axially relative to the pressure jacket 16. Therod 72 may be movable axially relative to the pressure jacket 16 by asolenoid or a mechanical linkage arrangement operatively connected tothe piston 19 (shown in FIG. 3). The compressible ring 112 isoperatively connected with the actuation mechanism 70 such that movementof the actuation mechanism 70 between the disengaged position or stateand the engaged position or state also moves the compressible ring 112between a disengaged position (FIG. 11A) and an engaged position (FIG.11B).

With continued reference to FIGS. 11A-11B, the at least one syringeretaining element 60 has the compressible ring 112 at least partiallypositioned within a pocket 78 extending radially outward into theinterior surface 28 of the pressure jacket 16. The compressible ring 112is circumferentially continuous around a circumference of the interiorsurface 28 of the sidewall 24 of pressure jacket 16. The compressiblering 112 may be made from an elastomeric material that is resilientlydeformable by contact with the actuation mechanism 70.

With continued reference to FIGS. 11A-11B, the pocket 78 has a firstinclined surface 80 at its distal end that guides the movement of thecompressible ring 112 between the disengaged position and the engagedposition. The first inclined surface 80 may be configured to guide thecompressible ring 112 radially inward relative to the interior surface28 of the pressure jacket 16. In some examples, the compressible ring112 may have a second inclined surface 114 that corresponds to the firstinclined surface 80 of the pocket 78. In use, the second inclinedsurface 114 of the compressible ring 112 is configured to engage thefirst inclined surface 80 of the pocket 78 such that the compressiblering 112 is compressed between the actuation mechanism 70 and the firstinclined surface 80, thereby displacing at least a portion of thecompressible ring 112 radially inward from the disengaged position (FIG.11A) and the engaged position (FIG. 11B). Similarly, the distal end ofthe rod 72 may have a third inclined surface 115 configured to guide theproximal surface of the compressible ring 112 inward. In certainexamples, the compressible ring 112 may have a fourth inclined surface117 on its proximal surface that corresponds to the third inclinedsurface 115 of the rod 72. In use, the fourth inclined surface 117 ofthe compressible ring 112 is configured to engage the third inclinedsurface 115 of the rod 72 such that the compressible ring 112 iscompressed between the actuation mechanism 70 and the third inclinedsurface 115. As the sidewall 38 of the syringe 30 expands radiallyoutward under pressure, the sidewall 38 of the syringe 30 contacts thecompressible ring 112 and the interior surface 28 of the pressure jacket16. In this manner, the syringe 30 becomes engaged with the pressurejacket 16 by a surface-to-surface contact between the compressible ring112 and the interior surface 28 of the sidewall 24 of pressure jacket 16with the sidewall 38 of the syringe 30. Due to such surface-to-surfacecontact, the syringe 30 is prevented from moving axially in the distaldirection under the proximally directed force of the piston 19 (shown inFIG. 1).

With reference to FIGS. 12A-12C, the pressure jacket 16 has a lip seal116 at least partially positioned within a pocket 78 extending radiallyoutward into the interior surface 28 of the pressure jacket 16. The lipseal 116 is circumferentially continuous around a circumference of theinterior surface 28 of the sidewall 24 of pressure jacket 16. The lipseal 116 may be made from an elastomeric material and is configured forsurface-to-surface contact with the distal end 34 of the syringe 30 whenthe syringe 30 is inserted into the throughbore 26 of the pressurejacket 16. The lip seal 116 is configured to prevent fluid from thesyringe 30 from entering into the space between the exterior surface ofthe syringe 30 and the interior surface 28 of the pressure jacket 16.For example, in many cases the frictional force between the sidewall 24of pressure jacket 16 and the sidewall 38 of the syringe 30 may bereduced if liquid from the syringe seeps between the contact pointsbetween the syringe 30 and the pressure jacket 16. This effect may beeliminated or reduced by the lip seal 116.

With reference to FIG. 13A-13B, the pressure jacket 16 may have at leastone syringe retaining element 60 that is recessed radially outward intothe interior surface 28 of the sidewall 24 of pressure jacket 16 todefine at least one recess 118. In some examples, the at least onerecess 118 may be circumferentially continuous around a circumference ofthe interior surface 28 of the sidewall 24 of pressure jacket 16. Inother examples, the at least one recess 118 may be discontinuous in acircumferential direction around the circumference of the interiorsurface 28 of the sidewall 24 of pressure jacket 16. In some examples,two or more recesses 118 may be axially spaced apart from one another.

With continued reference to FIGS. 13-13B, the at least one syringeretaining element 60 may have a sleeve 120 received within thethroughbore 26 of the pressure jacket 16 and positioned between theinterior surface 28 of the sidewall 24 of pressure jacket 16 and theexterior surface of the sidewall 38 of the syringe 30. The sleeve 120may have at least one groove 122 that protrudes radially outwardrelative to a body 124 of the sleeve 120. In some examples, the at leastone groove 122 may be circumferentially continuous around acircumference of the sleeve 120. In other examples, the at least onegroove 122 may be discontinuous in a circumferential direction aroundthe circumference of the sleeve 120.

The sleeve 120 is axially movable relative to the pressure jacket 16,such as by an actuation mechanism 70, between a first position (FIG.13A) and a second position (FIG. 13B). In various examples, theactuation mechanism 70 may be a mechanical mechanism, an electricalmechanism, an electromechanical mechanism, a pneumatic mechanism, ahydraulic mechanism, or a combination of any of these mechanisms. Insome examples, the actuation mechanism 70 may be a rod 72 that ismovable axially relative to the pressure jacket 16 to engage a proximalend of the sleeve 120. The rod 72 may be movable axially relative to thepressure jacket 16 by a solenoid or a mechanical linkage arrangementoperatively connected to the piston 19 (shown in FIGS. 4A-4B).

The at least one groove 122 is configured for being received within theat least one recess 118 on the pressure jacket 16 when the sleeve 120 isin the first position (FIG. 13A). With the sleeve 120 in the firstposition, a clearance space is provided between an interior surface ofthe sleeve 120 and the exterior surface of the syringe 30 to permit aready insertion of the syringe 30 within the pressure jacket 16. Whenthe sleeve 120 is moved axially in the distal direction (arrow C in FIG.13A), the at least one groove 122 is displaced from the at least onerecess 118, thereby reducing an internal diameter of the sleeve 120 froma first diameter D6 (shown in FIG. 13A), to a second diameter D7 (shownin FIG. 13B) that is smaller than the first diameter D6. With the atleast one sleeve 120 is the second position, the interior surface of thesleeve 120 is in surface-to-surface contact with the exterior surface ofthe syringe 30. Due to such surface-to-surface contact, the syringe 30is prevented from moving axially in the distal direction under theproximally directed force of the piston 19. In this manner, movement ofthe syringe 30 in the distal direction relative to the pressure jacket16 can be prevented.

With reference to FIG. 14, in another embodiment, the pressure jacket 16may have a first portion 16 a and at least one second portion 16 bseparable from the first portion 16 b in a plane along the longitudinalaxis 23 of the pressure jacket 16. The first portion 16 a and the atleast one second portion 16 b are movable relative to one another in afirst direction (arrow D) to increase a space therebetween and allow forinsertion of the syringe 30 (shown in FIGS. 4A-4B) within thethroughbore 26. The first portion 16 a and the at least one secondportion 16 b are also movable in a second direction (arrow E) todecrease a space therebetween and engage the exterior surface of thesyringe 30 in a surface-to-surface contact with at least a portion ofthe interior surface 28 of the sidewall 24 of pressure jacket 16.

With continued reference to FIG. 14, a guide mechanism 126 is providedon the pressure jacket 16 and/or the injector 10 (shown in FIGS. 1-2).The guide mechanism 126 is configured for guiding the movement of thefirst and at least one second portions 16 a, 16 b of the pressure jacket16 between a first position, wherein the first and at least one secondportions 16 a, 16 b are separated from one another to allow insertion orremoval of the syringe 30 from the pressure jacket 16, and a secondposition, wherein the first and at least one second portions 16 a, 16 bare moved toward each other to engage the syringe 30 therebetween. Insome examples, the guide mechanism 126 may have a first ramp 128 a onthe exterior of at least one of the first and at least one secondportions 16 a, 16 b and a second ramp 128 b movable relative to thefirst ramp 128 a. By moving the second ramp 128 b relative to the firstramp 128 a, the first and at least one second portions 16 a, 16 b can bemoved closer together or further apart from one another. With the firstand at least one second portions 16 a, 16 b of the pressure jacket 16 inthe second position, the interior surface 28 of the pressure jacket 16is in surface-to-surface contact with the exterior surface of thesyringe 30. Due to such surface-to-surface contact, the syringe 30 isprevented from moving axially in the distal direction under theproximally directed force of the piston 19 (shown in FIG. 1). In thismanner, movement of the syringe 30 in the distal direction relative tothe pressure jacket 16 can be prevented.

With reference to FIGS. 15A-15B, in one embodiment, the pressure jacket16 has at least one syringe retaining element 60 that is configured formovement between a disengaged position or state (FIG. 15A) and anengaged position or state (FIG. 15B) due to movement of an actuationmechanism 70. In some examples, at least one pair of syringe retainingelements 60 is provided opposite one another. The actuation mechanism 70may be configured to rotate at least a portion of the at least onesyringe retaining element 60 about a pivot point 130.

With continued reference to FIGS. 15A-15B, the at least one syringeretaining element 60 has a first portion 60 a extending in a firstdirection away from the pivot point 130 and a second portion 60 bextending in a second direction away from the pivot point 130. In someexamples, the first and second portions 60 a, 60 b may be connected toone another such that they pivot together around the pivot point 130. Inother examples, the first and second portions 60 a, 60 b may beindependently pivotable about the pivot point 130. The at least onesyringe retaining element 60 is operatively connected with the actuationmechanism 70 such that movement of the actuation mechanism 70 causes theat least one syringe retaining element 60 to move between a disengagedposition (FIG. 15A) and an engaged position (FIG. 15B). In thedisengaged position, the first portion 60 a is positioned away from thethroughbore 26 to prevent interference between the at least one syringeretaining element 60 and the syringe 30 during insertion and removal ofthe syringe 30 from the throughbore 26. In the engaged position, the atleast one syringe retaining element 60 is rotated about the pivot point130 to move the first portion 60 a radially inward to engage at least aportion of the frusto-conical distal end 34 of the syringe 30. In theengaged position, at least a portion of the second end 60 b isconfigured to be extended radially inward into the throughbore 26 of thepressure jacket 16 to contact at least a portion of the sidewall 38 ofthe syringe 30. During an injection procedure, radial expansion of thesyringe 30 increases a contacting force between the sidewall 38 of thesyringe 30 and the second portion 60 b to limit or prevent axialmovement of the syringe 30 relative to the pressure jacket 16. Suchaxial movement of the syringe 30 is further limited or prevented byinteraction of the first portion 60 a with the frusto-conical distal end34 of the syringe 30.

In some examples, the at least one syringe retention member 60 may bemovable within the sidewall 24 of the pressure jacket 16. For example,the at least one syringe retention member 60 may be in the form of amovable member, such as an “e-clip”, that is movable within thethroughbore 26 with movement of the syringe sidewall 38. When thesyringe 30 is pressurized, such as during an injection procedure, themovable member may move into a groove (not shown) on the interiorsurface 28 of the sidewall 24 of pressure jacket 16. In this manner, themovable member can be immobilized to define a surface against which thesyringe sidewall 38 can be restrained to prevent or limit axial movementof the syringe 30 within the pressure jacket 16. In other examples, theat least one syringe retaining element 60 may be a movable element thatis movable into the sidewall of the pressure jacket 16 during insertionof the syringe 30 but moves out of the sidewall as the syringe sidewall38 is expanded against the interior surface 28 of the sidewall 24 ofpressure jacket 16 during a fluid injection procedure. Such movablemember may be a ball that moves radially outward when the syringe 30 isinserted but moves radially inward when the syringe 30 is pressurizedand acted upon by the piston 19.

With reference to FIG. 16, load transfer efficiency of a pressure jacket16 having at least one syringe retaining element 60 according to oneembodiment of the present disclosure is shown as a function of fluidpressure inside the syringe 30. The X-axis in the graph shown in FIG. 16represents the pressure (in psi) within the syringe 30, while the Y-axisrepresents a percentage of axial load on the syringe 30 imposed by thepiston 19 that is transferred to the distal end of the syringe 30. Theamount of load absorbed by the interaction between the pressure jacketwith the at least one syringe retaining element 60 and the syringe isshown as P=100−Y, where Y is the efficiency value. At low pressures (<50psi), the axial frictional force at the surface-to-surface interfacebetween the exterior of the syringe 30 and the interior surface 28 ofthe pressure jacket 16, including the surface-to-surface contact betweenthe exterior of the syringe 30 and the at least one syringe retainingelement 60, is insufficient to absorb most of the axial load on thesyringe 30. For example, at 50 psi, approximately 80% of the pressure istransferred to the distal end of the syringe 30 and only 20% is absorbedby the interaction between the pressure jacket and the syringe. As shownin FIG. 16, at high pressures. Such as 200 psi, the radial expansion ofthe syringe 30 against the interior surface 28 of the pressure jacket 16and the consequent engagement between the exterior surface of thesyringe 30 with the at least one syringe retaining element 60 transfers45% or more of the axial load imposed on the syringe 30 to the pressurejacket 16 . In this manner, approximately 55% of the axial load on thesyringe 30 is transferred to the holding bracket 44. Extrapolating tofluid pressures exceeding 300 psi, the pressure jacket 16 and the atleast one syringe retaining element 60 absorb approximately 50% of theaxial load imposed on the syringe 30 to the pressure jacket 16.

Although the disclosure has been described in detail for the purpose ofillustration based on what is currently considered to be the mostpractical and preferred examples, it is to be understood that suchdetail is solely for that purpose and that the disclosure is not limitedto the disclosed examples, but, on the contrary, is intended to covermodifications and equivalent arrangements. For example, it is to beunderstood that the present disclosure contemplates that, to the extentpossible, one or more features of any example can be combined with oneor more features of any other example.

We claim:
 1. A pressure jacket configured for removably connecting to aninjector head of a fluid injector, the pressure jacket comprising: anopen distal end, an open proximal end, and a sidewall defining athroughbore extending between the distal end and the proximal end alonga longitudinal axis, the throughbore configured for receiving at least aportion of a syringe; and at least one syringe retaining elementpositioned at least partially within the throughbore, wherein the atleast one syringe retaining element comprises at least one protrusionprotruding radially inward from an interior surface of the sidewall ofthe pressure jacket, wherein the at least one protrusion is configuredto engage at least a portion of the syringe during pressurized deliveryof fluid from the syringe due to radial expansion of the cylindricalsidewall of the syringe to prevent or limit a distal movement of thesyringe relative to the pressure jacket.
 2. The pressure jacket of claim1, wherein the at least one protrusion is circumferentially continuousor discontinuous around a circumference of the interior surface of thesidewall of the pressure jacket.
 3. The pressure jacket of claim 1,wherein the at least one protrusion comprises a plurality of protrusionspositioned on the interior surface of the sidewall of the pressurejacket.
 4. The pressure jacket of claim 3, wherein the at least onesyringe retaining element further comprises at least one expansionpocket recessed radially outward into an interior surface of thesidewall of the pressure jacket.
 5. The pressure jacket of claim 4,wherein a volume of the at least one expansion pocket is selected toprevent plastic yield of a sidewall of the syringe during thepressurized delivery of fluid from the syringe exceeding a predeterminedthreshold pressure.
 6. The pressure jacket of claim 4, wherein the atleast one expansion pocket is circumferentially continuous ordiscontinuous around a circumference of the interior sidewall of thepressure jacket.
 7. The pressure jacket of claim 4 wherein the at leastone expansion pocket comprises a plurality of expansion pockets axiallyoffset from each other.
 8. The pressure jacket of claim 4, wherein theat least one expansion pocket comprises one or more through holes thatextend through the sidewall of the pressure jacket.
 9. The pressurejacket of claim 1, wherein a volume of the at least one protrusion isselected to maintain a predetermined axial restraining force due toradial expansion of at least a portion of a sidewall of the syringeagainst the at least one protrusion during the pressurized delivery offluid from the syringe.
 10. The pressure jacket of claim 1, wherein theat least one protrusion is dimensioned to allow insertion of the syringeinto the throughbore of the pressure jacket during loading and providesufficient axial restraining force when the cylindrical sidewall of thesyringe sidewall is expanded against the sidewall of pressure jacketunder pressure during an injection procedure.
 11. The pressure jacket ofclaim 1, wherein the at least one protrusion is integrally formed withthe pressure jacket.
 12. The pressure jacket of claim 1, wherein the atleast one protrusion is removably or non-removably connected to thepressure jacket.
 13. The pressure jacket of claim 12, wherein the atleast one protrusion is a label attached to the inner surface of thepressure jacket.
 14. The pressure jacket of claim 1, wherein the atleast one protrusion has a roughened surface.
 15. A fluid injector fordelivering fluid to a patient, the fluid injector comprising: at leastone injector head; and at least one pressure jacket removably connectedto the at least one injector head, the at least one pressure jackethaving an open distal end, an open proximal end, and a sidewall defininga throughbore extending between the distal end and the proximal endalong a longitudinal axis, the throughbore configured for receiving atleast a portion of a syringe; and at least one syringe retaining elementpositioned at least partially within the throughbore, wherein the atleast one syringe retaining element comprises at least one protrusionprotruding radially inward from an interior surface of the sidewall ofthe pressure jacket, wherein the at least one protrusion is configuredto engage at least a portion of the syringe during pressurized deliveryof fluid from the syringe due to radial expansion of the cylindricalsidewall of the syringe to prevent or limit a distal movement of thesyringe relative to the pressure jacket.
 16. The fluid injector of claim15, wherein the at least one syringe retaining element further comprisesat least one expansion pocket recessed radially outward into an interiorsurface of the sidewall of the pressure jacket.
 17. The fluid injectorof claim 15, wherein the at least one protrusion comprises a pluralityof protrusions positioned on the interior surface of the sidewall of thepressure jacket.
 18. The fluid injector of claim 15, wherein the atleast one protrusion is dimensioned to allow insertion of the syringeinto the throughbore of the pressure jacket during loading and providesufficient axial restraining force when the cylindrical sidewall of thesyringe sidewall is expanded against the sidewall of pressure jacketunder pressure during an injection procedure.
 19. The fluid injector ofclaim 15, wherein the at least one protrusion is integrally formed withthe pressure jacket.
 20. The fluid injector of claim 15, wherein the atleast one protrusion is a label attached to the inner surface of thepressure jacket.